I felt compelled to write up something to say just how awesome the Portableapps Suite is. This is a program made for flashdrives, meant to create easier accessibility for programs, as well as a bunch of apps to go with it. There is such a vast amount of apps, but the ones of the top of my head:

• WinMerge - This lets you compare files and merge them, and it even has syntax highlighting. I know someone a long time ago was looking for something like this.
• Notepad++ - I know how much BYOND loves it's notepad++, and here's a portable version of it!
• Breakout - Who doesn't love a classic game of breakout? Well, not so classic, but still incredibly fun!
• GIMP - If this wasn't free, I'd have gotten my moneys worth on this one. I use GIMP all the time, everywhere I go, because I am so anti-photoshop, and my school somehow got rid of paint.exe.
• Firefox - Not so much my favorite, I actually put opera in there, myself..
• Pidgin - Again, not so much my favorite, as I've actually put trillian there, but I know there are some pidgin fanboys probably reading this.
• Openoffice - Definitely amazing. I no longer have any of this installed on my computer, just because I have it here. I'm just that cool.
• Mac-on-stick - Ever want to run the Mac OS from a flashdrive? Well, it's Mac OS 7, but it's still there.
• Kee-pass - Definitely awesome. I use this to store all my passwords in, as I take games with me everywhere I go (some of them are mmorpgs, really small ones, but still), and this keeps all my passwords safe :D.
• Infrarecorder - A portable CD/DVD burner. Yay!

I think I've mentioned quite a few. Some you may have heard of, some hopefully not. If you have a spare flashdrive, definitely check this utility out!

On a side note:
Even if you don't want to use some portable programs, you can put your own in. You'd just have to put forth a bit more effort -- putting the files in the portableapps folder yourself. Not a big deal, though, right?